Insulating Your Home

According to the U.S. Energy Information Administration (EIA) on average, more than half (51% in 2015) of a household’s annual energy consumption is for space heating and air conditioning. Though, seasonal heating and cooling needs vary significantly by geographic location, home size and structure, and equipment and fuels used. Nonetheless, heating and cooling your home uses more energy and costs more money than any other system in your home.

I live in climate zone 4 and made my decisions on insulation based those factors in 2008. My brother who just bought new home (from the 1950’s) lives in climate zone 5 in the Boston area. He is looking to add insulation to his home.  So, I am reviewing the choices in 2021. For the insulation project, the attic and accessible areas of the basement and crawl spaces were inspected for adequate insulation.

from DOE

For my home built in 2004 with duct work for my heat pump in the attic, I followed the recommendations by the Oak Ridge National Laboratory. The attic, crawl spaces, eves, ductwork,underside of a large portion of the main level floor were insulated withcellulose (in the attic) and fiberglass batting insulation in the basement andfloor. The pipes, end caps, knee wall, sump pumps and all identified areas were sealed, the garage was insulated and an insulated garage door installed. I have a separate garage with no living space above it, I used it to test Icynene foam insulation.

My total electricity bills for the following 12 months were 27% less than I paid in the 12 months before I added the additional insulation to the house, and the winter liquid propane usage (as measured in volume use December through March both years) was reduced by 25%. Also, the overall comfort in the bedroom over the garage and the master bedroom has been vastly improved. I was very surprised at the energy savings for what was a well insulated home. The payback on this project was under 4 years, unbelievably good.

I used blown in cellulose for several because it was inexpensive, but also because it is inert and I was adding insulation to a home that already had some blown in cellulose. There was no off-gassing from urethane based foams, no fiberglass fibers to get into the air handling system. When I insulated my home in 2008 various foams on the market were changing due to the removal of some foaming agents from the market. I was concerned about having a negative impact on air quality that would be extremely difficult to remedy. Todaythe Environmental Working Group says: “spray foam containing a chemical knownas methylene diphenyl diisocyanate, or MDI, which can cause asthma and lungdamage in exposed workers. Spray foam can also contain the toxic flameretardant TCPP. If mistakes are made during installation, sprayed-on insulationfoam is difficult to remove.”

For loose-fill insulation, each manufacturer must determine the R-value of its product at settled density and create coverage charts showing the minimum settled thickness, minimum weight per square foot, and coverage area per bag for various total R-values. This is because as the installed thickness of loose-fill insulation increases, its settled density also increases due to compression of the insulation under its own weight.  Thus, the R-value of loose-fill insulation does not change proportionately with thickness. The manufacturers’ coverage charts specify the bags of insulation needed per square foot of coverage area; the maximum coverage area for one bag of insulation; the minimum weight per square foot of the installed insulation; and the initial and settled thickness of the installed insulation needed to achieve a particular R-value.

Spray foam comes in two types- open-cell foam or closed-cell foam. Closed cell foam has the highest R-value of any insulation, up to R-7 per inch, but can be expensive; open-cell foam insulation values are around R-3 to R-4 per inch of thickness. Closed cell can also serve as a moisture barrier. Spray foam insulation should be installed by a professional, since it is tricky to do right and almost impossible to undo. In order to spray in insulation into an attic that has some existing insulation, all the old insulation would have to be removed, or the new spray in insulation would have to be applied to the roof deck and knee walls. This can trap moisture between the roof shingles and foam mass. It could prevent mold in the attic, but allow rotting of the roof elements. 

Before insulating, seal any air leaks and make roof and other necessary repairs. If it is located in a conditioned part of the house, also remember to insulate and air seal your attic access. Insulate and air seal any knee walls -- vertical walls with attic space directly behind them -- in your home as well. If the air distribution system is not within the conditioned space but within the attic, insulating the rafters will enclose the distribution system. Finally, the DOE advises if you live in a hot or warm climate, consider installing a radiant barrier in your attic to reduce summer heat gain.

According to the U.S. EPA:

• Spray foam application generates isocyanate vapors and aerosols.
• Research data indicate that inhalation exposures during spray foam insulation will typically exceed Occupational Safety and Health Administration (OSHA) occupational exposure limits and require skin, eye and respiratory protection.
• Vapors and aerosols can migrate through the building if the installation area is not properly isolated and ventilated.
• After application, vapors may linger in a building until properly ventilated and thoroughly cleaned.

These days, foam insulation is growing in popularity, especially in colder climates where higher insulation values are required by code. Available foam insulation materials include:

• Cementitious
• Phenolic
• Polyisocyanurate (polyiso)
• Polyurethane.

Polyurethane is the most commonly used right now according to DOE. Some less common types include Icynene foam (what I used in my garage attic) and Tripolymer foam. Icynene foam can be either sprayed or injected, which makes it the most versatile. It also has good resistance to both air and water intrusion. Tripolymer foam—a water-soluble foam—is injected into wall cavities. It has excellent resistance to fire and air intrusion.

Foam insulation products and installation usually cost more than traditional batt or blown in insulation. However, foam insulation has higher R-values and forms an air barrier, which can eliminate some of the other costs and tasks associated with weatherizing a home, such as caulking, applying housewrap and vapor barrier, and taping joints. When building a new home, this type of insulation can also help reduce construction time and the number of specialized contractors, which saves money for the builder so it is often used in new construction.

Liquid foam insulation materials can be sprayed, foamed-in-place, injected, or poured. Foam-in-place insulation can be blown into walls, on attic surfaces, or under floors to insulate and reduce air leakage. Closed cell installations can yield a higher R-value than traditional batt insulation for the same thickness, and can fill even the smallest cavities, creating an effective air barrier. You can use the small pressurized cans of foam-in-place insulation to reduce air leakage in holes and cracks, such as window and door frames, and electrical and plumbing penetrations. In the end the type of insulation you used is your decision.

Energy Consumption in the US 2010

According to the US Energy Information Administration, the statistics branch of the Department of Energy, the US used 98 quadrillion BTU last year. Energy sources are measured in different physical units depending on the type of energy source: barrels of oil, cubic feet of natural gas, tons of coal, kilowatt hours of electricity. In the United States, British thermal units (Btu), a measure of heat energy, is a commonly used unit for comparing different types of energy. In 2010, U.S. primary energy use equaled 98 quadrillion (=E15, or one thousand trillion) Btu. If it helps to visualize this any better, that is equivalent to about 2,471 Mtoe (million tons of oil equivalent) the energy measurement standard used by the International Energy Agency, IEA, the keeper of world statistics. In a world with seven billion people the United States is estimated to have 310 million people, about 4% of the world’s population, 7% of the land mass and use about 14% of the energy (depending on how fast China and India are growing since the world energy data is about two years old).

In the United States the US Energy Information Administration collects and reports the energy statistics in quadrillion BTUs and has recently reported the summary data for 2010. These statistics paint a picture of who we are today. The major energy sources in the United States are petroleum-gas and oil (37%), natural gas (25%), coal (21%), nuclear (9%), and renewable energy primarily biomass and hydro power generation (8%). The United States only produces about 75% of the energy we consume, the shortfall is imported petroleum. The major users are heating of residential and commercial buildings (11%), industry (20%), transportation including cars, trucks, trains, planes and ships (27.4%), and electric power generation (40%).

The slightly complicated chart above shows the types of fuel and the sector that consumes it. Looking at petroleum, you can see that it supplies 37% of our energy needs. Transportation, cars, trucks, trains, planes and ships, uses 71% of petroleum and that petroleum provides 94% of the total energy used in transportation. Industry uses 22% of the total petroleum consumed by the United States to supply 40% of the energy used by industry. Studying all the details of the chart tells you a lot about the United States in 2010. It will also allow you to understand the impact that policies, regulation and scientific advances might have on the country.

For example, 92% of coal mined in the United States is used to generate electricity, regulations like the EPA’s Mercury and Air Toxics Standards and the Cross-State Air Pollution Rule affecting electricity generation are likely to impact coal use, cost of electricity, mining and mining regions. In 2010, of the 1,085.3 million short tons of coal produced in the United States, about 7.5% was exported, so if the number of coal fired electrical plants is decreased, the demand for coal to produce electricity is reduced, the amount of coal mined in the United States will decrease, the number of coal miners and employees of coal companies will decrease, the trains transporting coal and their employees will not be necessary, and the cost of electricity will increase as the electrical power industry builds new generation plants burning other fuels.
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Some primary energy sources, such as nuclear and coal, are entirely used in one sector, electrical generation. Others, like natural gas and renewables, are more evenly distributed across sectors. Similarly, while transportation is almost entirely dependent on petroleum, electric power uses a variety of fuels. Because the United States is the world’s largest oil importer, it may seem surprising that it also exports about 2 million barrels a day of refined petroleum products. It seems were are also an excellent oil refiner on the easily accessed Gulf Coast. Petroleum is used primarily for gasoline for cars (55%), diesel for trucks and heating oil (23%), propane and liquefied petroleum gases used in homes and farms for cooking, heating, and jet fuel (9%). The five biggest sources of net crude oil imported to the United States in 2010 were: Canada (25%), Saudi Arabia (12%), Nigeria (11%), Venezuela (10%), Mexico (9%). Policy decisions about a future Keystone pipeline may change that in the future. U.S. crude oil imports grew rapidly from mid-20th century until the late 1970s, but fell sharply from 1979 to 1985 because of restructuring the economy (manufacturing as a component of the economy was reduced), conservation, and improved efficiency. After 1985, the upward trend resumed, peaking at 10.1 million barrels per day in 2005, and falling to 9.2 million barrels per day in 2010.

Natural gas is the source of 25% of the energy consumed in the United States and in 2010 was used almost equally for industry, electrical generations and residential and commercial heating. Most, but not all, of the natural gas consumed in the United States is produced in the United States. Some natural gas is imported to the United States in the older Keystone pipelines. Natural gas is also being shipped to the United States as liquefied natural gas (LNG). U.S. natural gas production and consumption were nearly in balance through 1986 though U.S. production of natural gas peaked in 1973. From 1986 to 2006 consumption of natural gas outpaced production, and imports rose. Then in 2006 U.S. production of natural gas began to increase as a result of the development of more efficient and cost effective hydraulic fracturing techniques. In 2010 natural gas production in the United States reached the highest recorded annual total since 1973. Regulation and control of hydraulic fracturing will impact the cost of natural gas production in the United States, the availability of gas and the environmental impact to our natural resources.

In truth I am an old time engineer who learned to look at the world with a slide rule (calculators were just coming in and thought to be cheating). Through numbers I understand the world, policies and see relationships.

Fracking and Earthquakes

Two weeks ago I happened to talk about the responses of water levels in wells to earthquakes and the limits of our knowledge as to how and why this happens over distances of hundreds even thousands of miles. I questioned what this connection of groundwater to earthquakes might mean for groundwater in areas that are fracked. Fracking or hydraulic fracturing as it is more properly known is the pressurized injection of water with chemical additives into a geologic formation. The pressure used exceeds the rock strength and the fluid cracks open or enlarges fractures in the rocks and shale. As the formation is fractured, a “propping agent,” such as sand or ceramic beads, is pumped into the fractures to keep them from closing when the pumping stops and the pressure is released. Natural gas will flow from the fractures in the rock and shale into the wells increasing the recovery of the methane.

In hydraulic fracking in a shale formation to enhance recovery of natural gas on average 2-3 million gallons of chemicals and water is pumped into the shale formation at 9,000 pounds per square inch and literally cracks the shale or breaks open existing cracks and allows the trapped natural gas to flow. While geologists and engineers believe that there is little risk that the fracking “water,” a mix chemicals and water, will somehow infiltrate groundwater reserves though a fissure created by the fracking there are other routes of contamination and impact. It is believed that the intervening layers of rock would prevent a fissure from extending thousands of feet to the water table; there are other risks in how we build wells and fracture the shale. There have been documented cases of seepage into drinking water wells through improperly sealed or abandoned drilling wells. There are also places where groundwater is only several hundred feet above the gas reserves as they are in Wyoming and groundwater is more easily directly impacted by fracking.

The US Geological Survey has been studying the factors that impact the response of groundwater wells to earthquakes, including the magnitude and depth of the earthquake, distance from the epicenter, and the type of rock that surrounds the groundwater. The depth of the well, whether the aquifer is confined or unconfined, and well construction also influence the degree of water-level fluctuations in wells in response to seismic waves. It has been suggested that some aquifers may even act as resonators, which may amplify the response. The US Geological Survey has been able to add more data points to their information base this past week and someday we may know more about this relationship and groundwater itself, but right now all the US Geological Survey can do is observe and collect data.
http://va.water.usgs.gov/Gw_FS_2008.pdf

Dr. Cliff Frohlich of the University of Texas at Austin was part of a team of researchers who studied a series of small earthquakes that struck near Dallas, Texas in 2008 and 2009, in an area where natural gas companies had used fracking. The epicenter of the quakes turned out to be about half a mile from a deep injection well under the Dallas-Fort Worth International Airport used to dispose of the fracking fluid. The largest earthquake of the series measured 3.3 on the Richter scale, a very small earthquake. In a study that was published in the Bulletin of the Seismological Society of America, the researchers also reviewed records from US Geological Survey seismic-recording stations in Oklahoma and Dallas. It was concluded by the researchers that the fracking did not cause the earthquakes, but there seemed to be a relationship to the deep well injection of the fracking fluid to the earthquakes. The water caused the earthquakes.

This past spring, the Shale Gas Subcommittee of the Secretary of Energy Advisory Board was created to identify the measures that can be taken to reduce the environmental impact and improve the safety of shale gas production utilizing fracking. Dr. Mark Zoback of Stanford University was a member of the committee. He has studied the relationship of earthquakes to fracking and is a strong supporter of replacing coal with natural gas. He feels the risk of earthquake from fracking fluid disposal and all other risks from fracking are manageable. According to Dr. Zoback the risk could be mitigated by treating the water on the surface or shipping the water to a disposal well that isn’t near a fault. He felt the risk could be addressed by oil and gas companies identifying faults near potential well sites, and simply staying away from the faults.
http://www.ouramazingplanet.com/texas-earthquakes-natural-gas-mining-fracking-1152/
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2011/08/28/BU0L1KS4BU.DTL

Our ability to recover natural gas buried a mile or more beneath the earth has increased. Advances in horizontal drilling which allows a vertically drilled well to turn and run thousands of feet laterally through the earth combined with advances in hydraulic fracking, the pumping of millions of gallons of chemicals and water into shale at high pressure have increased our ability to recover natural gas from shale. Hydraulic fracking is a technology that was unknown 60 years ago. In the past decade the advances in drilling and fracking technology have been adapted to exploit gas in the Barnett shale in the Fort Worth Basin in Texas and applied to a series of major shale gas deposits that could not have been viable without the advances in drilling and fracking. The Fayetteville shale, the Haynesville shale, the Marcellus shale reserves all in the United States and the Horn River shale in Canada are now accessible. At the current rate of natural gas consumption North America is reported to have a 100-year supply of proven, producible reserves and even with expanded use of natural gas, there is more than a generation of currently accessible reserves. This natural gas could profoundly change the future of our nation and would we live in; however we need to be cautious about what other impacts fracking might have especially to hydraulic balance of groundwater.